Table of Content

25 November 2015, Volume 26 Issue 22

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A One-input Three-rotation Output Parallel Mechanism and Its Kinematics Design  Used for Shoulder Rehabilitation

Shen Huiping, Yang Liangjie, Deng Jiaming, Zhang Xiaoyu, Shen Xiaojun

2015, 26(22):  2983-2988. 

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According to the physiological characteristics and rehabilitation mechanism of human shoulder,a three-rotation parallel mechanism used in rehabilitation training of human ball-and-socket shoulder joint was proposed, and a single-input and three-rotation output parallel shoulder rehabilitation training device was designed. Through the analysis of topological structure of the mechanism, its coupling degree was calculated to be zero, so its forward and inverse displacement solution was directly deduced, without the needs for complex algebraic elimination derivation calculation. The motion simulation was finished by ADAMS and the feasibility of the design was confirmed by its simulation results. Finally, the rehabilitation training virtual prototype was designed by UGNX software, which laid a foundation for the design and manufacture of the prototype.

Research on Design and Pitch Surface Shaping of New Type High-order Non-circular Gear

Lü Gang, Fan Shouwen, Li Guanghui, Tong Shuiguang, Xiao Renyuan

2015, 26(22):  2989-2995. 

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Archimedes spiral and Pascal curve were firstly used to design NBGs, the pitch surface mathematical model of NBGs was deduced. Aiming at cusp problems of pitch surface of high-order NBG pairs, a section pitch surface curve of generation cutter was considered as pitch surface lied in high-order NBGs cusp. According to motion relationship between pitch surface of cutter and that of the high-order NBGs, pitch surface shaping model of the high-order NBGs was established and generation algorithm of NBGs teeth profile was developed.  High-order Archimedes spiral bevel gear and quadratic curve bevel gear were selected as cases to verify design practicability and pitch curve shaping method of high-order NBG.

Study on Motion Control Way for Acoustic Suspended Particles Inside a Component

Wang Yaxing, Wu Liqun, Lin Zhipeng, Ye Miaohong, Zhuang Long

2015, 26(22):  2996-3001. 

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In order to machine the structure inside a component directly, a new processing method was put forward with the ultrasonic suspension technology. Firstly, a controlled particle motion model was established through theoretical study of ultrasonic suspension, and then a new test system was designed. After some suspended particles' control movement tests, relationship among the suspension forces and particle diameters, channel sizes, transmission thicknesses was obtained. Results show that the proposed method can drive the particles in 3D space moving to any position freely with higher accuracy. The control scheme is feasible and inspiring.

Reliability  Evaluation  of Complex System  with Imperfect Protections

Ruan Yuanpeng, Li Xiao, Cui Jian

2015, 26(22):  3001-3007. 

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Because  of the  drawbacks of current researches when dealing with the problems of  evaluating the reliability of a  complex system containing components with propagated failures,a  cellular  automata-based  Monte  Carlo  simulation algorithm was presented to  deal  with the complex problems,which combined  the  advantages of  parallel computing  of cellular automata and the flexibility of Monte Carlo simulation technology.The proposed algorithm considered the influences  of imperfect protections on system reliability and overcame the limitations of system structure and the number of components. Finally, two given examples illustrated the validity of the proposed algorithm  respectively  and
the method to analyze system reliability.

Electronic Hydraulic Steering System and Its PID Controller Applied to Third Axle of Multi-axle Vehicles

Qian Lijun, Hu Weilong, Qiu Lihong, Liu Shaojun

2015, 26(22):  3008-3013. 

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The electronic hydraulic steering system of a third axis aimed at reducing the wear of the rear tires of the multi-axis vehicles. The actuator of electric hydraulic steering system and the working principles of the centering and self-locking cylinder of hydraulic system were focused.An expected angle of the third axle was fitted based on the Ackerman angle theorem. A model of electronic hydraulic steering system was built. A fractional order PID controller and the algorithm of fractional order PID controller parameters were put forward．At last  the simulation  analyses, a bench test and a vehicle test were conducted. The fitting results show that the residual square between the expected values and the real values of the angles of the third axle are within 0.16 and the fitting degree is above 0.985 when the speed of vehicle is as  10m/s or 20m/s. And the simulation results show that the system controlled by fractional order PID controller has smaller overtime and shorter adjusting time than the one of integral order PID controller. The bench test results show the errors between the expect values and the real values of the third axle are within (±0.3°) when the speed of vehicle is as 10m/s or 20m/s. Vehicle experimental  results show that tire wear are reduced no matter in the case of no-loaded or full-loaded after the fractional order PID control electric hydraulic steering system is installed.

Fabrication and Experiments of Brazed Diamond Grinding Disc for Dry Grinding

Wang Bo, Xiao Bing, Shao Mingjia,

2015, 26(22):  3014-3020. 

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In order to solve the problems of low grinding efficiency,big sparks,dusty and low security issues of  traditional resin grinding wheel in dry grinding  for high-strength steel,the feasibility of taking advantage of brazed diamond technique for preparing grinding disc  was studied and the countermeasures were proposed.A  new diamond arrangement process  was adopted,and the vacuum brazed grinding disc was prepared by using of  Ni-Cr alloy.Tests of dry grinding for  high-strength steel AH36  were proceeded.The results show that, compares with conventional resin grinding wheel,the efficiency ratio of  brazed diamond  grinding disc increases 40%  and the grinding life enhances more than 12 times.The debris of brazed diamond grinding disc after grinding have a larger average size  and variety. Without the presence of molten debris and almost no wear debris adhered to diamond surfaces,the effective temperature control of novel disc is proven  during the dry grinding.

Research on Frame Packing Mechanism of Static Segment in Automobile FlexRay Network

Wang Yuefei, Zhang Heng, Zhang Yasheng, Liu Hongjun

2015, 26(22):  3021-3027. 

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On the basis of analyzing FlexRay frame format and coding,the calculation formula of the length of static slot and bus utilization rate were obtained,and main factors that influenced bus  utilization rate were given.Some prerequisites of frame packing and exact calculation method of lower and upper bounds of the size of the payload segment were proposed.Finally, with the target of realizing highest bus utilization rate in super cycle,the  integer linear programming  model  was established to solve the problem of frame  packing and heuristic algorithm of solving the model was given.The  American socity of automotive engineers(SAE) experimental results demonstrate the effectiveness of the proposed method,which raises  the bus utilization rate,and reduces the execution time of algorithm.

Blind Mechanical Information Extraction Based on Singular Value Fusion

Wu Wenfeng, Li Hao, Zhu Lu

2015, 26(22):  3028-3033. 

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In order to extract the fault feature informations of mechanical equipment,a blind information extraction method  was proposed  based  on  singular value fusion.Firstly,by independent component analysis,the source signals were separated from mechanical vibration observation signals.Then the source signals were demodulated to get envelope signals and form envelope matrixes.The envelope matrixes were processed by singular value decomposition and then the singular value vectors (including singular value averages and singular value entropy) were extracted as feature information of the detected mechanical equipment. Secondly, the separating matrix was directly processed by singular value decomposition and its singular values could also be extracted as useful feature information. Lastly, the singular value vector was obtained by information fusion as final optimum feature information of the mechanical equipment. The experimental results of hydraulic gear pump indicate that this method can be applied to feature extraction of mechanical equipment effectively.

Frequency Characteristics Analyses  of   Penetrating  Missile and Penetration Overload  Signal Processing

Zhao Haifeng, Zhang Ya, Li Shizhong, Guo Yan

2015, 26(22):  3034-3039. 

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In order to solve the hard target penetration overload signals de-noising problem,this paper proposed a joint filtering method based on EEMD and WT. IMF components could be  got.Secondly,the original signals EEMD decomposition scale could  be drawn through comparing the power spectrum of each components with the original signals'.Then,the high-frequency components of IMF
were filtered based on the WT  threshold.Finally,the signals were  reconstructed by using the low-frequecy IMF components and the filtered high-frequency IMF components. Experiments show that proposed method can effectively extract the response frequency of missile body， eliminate high-frequency vibration and noise in the penetration.  The results of the proposed method can get better signal to noise ratio(SNR)  than  that  of  WT.And the integrated velocity and displacement time-history curves are close to the experiments.

Approach  to  Arbitrary Transportation of Suspended  Particles Based on  Ultrasonic Composite Field

Zhuang Long, Wu Liqun, Du Xibiao, Zhang Linan

2015, 26(22):  3040-3045,3050. 

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A particle suspension transport method  was proposed based on ultrasonic composite field.Firstly,the array focusing model and accumulated force equation were established based on phased array ultrasonic cells delay,then integrated with the standing wave ultrasonic field radiation force calculation method, the particle motion control model and driving force formula under the combined ultrasound field were introduced.Through the MATLAB simulation of complex ultrasound field, the factors that affected the focusing performance and control performance were analysed,and  the  preliminary test results were given and discussed.Finally,arbitrary control scheme of particle motion was put forward by compound ultrasonic driving field.

Vehicle State Estimation Based on Ant Colony Optimization Algorithm

Zhang Fengjiao, Wei Minxiang, Zhao Wanzhong

2015, 26(22):  3046-3050. 

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For time-varying characteristics of process noises and observation noise problems in vehicle state estimation, a new adaptive filtering algorithm was put forward. The new adaptive filtering algorithm was based on the 3-DOF nonlinear vehicle dynamics model, when UKF algorithm was applied to estimate vehicle state, the ant colony optimization algorithm was introduced at the same time. The adaptive functions of process noises and observation noises were achieved according to optimization principles based on objective function. The estimation precision increases greatly by using the new adaptive filtering algorithm. Robustness and accuracy of the ant colony optimization UKF algorithm were verified through the virtual experiments, the results will have important theoretical significance for the development of automobile active control system.

A Virtual Olfactory Generation Device for Visual-olfactory Perceptions

Yang Wenzhen, Wu Xinli, Yu Ling, Zhu Panfei

2015, 26(22):  3051-3056,3063. 

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This paper presented a virtual olfactory generation device for the visual-olfactory perceptions in virtual environments. This device was composed by a mechanical body and a control system, can output 3 odors in single or mixed models. By analyzing the pressed force, which was required by the perfume bottles, a quantitative aspirated odor mechanism was designed and  the mechanical body was manufactured. Then the control system was developed based on a serial communication and the performances of this device were tested, which included the response time and the movement precision. The experiential results show that the virtual olfactory generation devices has fast response time and high precision control features, can generate the stable odor in real-time, and present the realistic olfactory in virtual environments.

Forming Limit  Prediction  of  Tailor-welded  Blanks  Based  on GTN  Damage Model

Ma Xiangdong, Guan Yingping

2015, 26(22):  3057-3063. 

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The  GTN  damage model was established to predict the forming limit of TWBs,and the damage parameters were determined by the use of finite element inverse method. Hemispherical punch bulging test process was simulated by the finite element software ABAQUS and coupled the Mises yield criterion with GTN damage model. Experiments of hemispherical punch bulging test were  designed,which changed specimen width to obtain complete forming limit diagram of TWBs in different strain conditions.Meanwhile, the prediction and experimental results were compared to validate the accuracy of GTN damage model.

Associated Simulation Model of  Key  Green Factors in Recycling and  Remanufacturing  System  of  Mechanical  Products

Deng Qianwang, Li Weiming, Li Xun, Liu Xiahui

2015, 26(22):  3064-3075,3115. 

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This paper analyzed the green factors of system from the perspective of systems engineering, then they were divided into one sets of control factors in view of technology and process and put into the other sets of green performance in light of economy, resources, environment, human factors.An associated simulation model was also proposed  via establishing the association rules, and  the output sets of green performance was studied  by using clustering analysis based  on the simulation results, thus obtaining 50 system factors. Then the system architecture  was established on the basis of interpretative structural matrix,after proposing a directed graph of the system structure. Finally, this structure was utilized to analyze  hierarchical relationships between the factors, in order to provide an optimization direction to the green outputs of the recycling and remanufacturing system.

Research  on  Inside-laser  Powder Feeding  Nozzle  for  Broadband  Laser  Cladding

Lei Dingzhong, Shi Shihong, Fu Geyan

2015, 26(22):  3076-3081. 

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In order to improve the situation of the uneven heating of metal powder existing in the current outside-laser powder feeding broadband laser cladding nozzle and the low coaxial coupling accuracy, a inside-laser coaxial powder feeding broadband laser cladding nozzle   was designed.The entire device was located inside the laser cladding nozzle,surrounded by laser beam,senting cladding powder to the laser molten pool.A flow channel was designed to realize the uniformity of inside-laser  powder feeding and  ensure the powder  was heated evenly and the direction of the powder velocity was perpendicular to the molten pool throughout.FLUENT software was used to analyze the divergence of powder to determine the size of the export channel spacing and the internal flow field of powder channel to determine the size of the device partially channel so that the turbulence at the outlet could be reduced and the best results of powder feeding could be achieved.Finally,the powder feeding nozzle for powder feeding test was  used to validate the experimental  effects  of powder feeding device.

Vibration  Analysis and  Prediction of Penumatic Wheel  in  Finishing Process

Cai Donghai, Ji Shiming, Zhang Heteng, Jin Mingsheng

2015, 26(22):  3082-3086. 

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In order to suppress the vibration of  pneumatic  wheel,the research   of  vibration analysis and prediction was done.Kinematic model of  the robot of  6-DOFs  was  conducted using  D-H method,the rotation angle of each joint of any given  posture and the overall stiffness matrix of the  robot were  obtained,The displacement of  the  pneumatic wheel  was obtained,based on the analyses of the  forces.The comparison was made between  the  displacement and the experimental result and the vibration prediction model expression was established.The model is helpful for posture optimization.

Analyses of Force Closed-loop Control Characteristics of 0.6MN Free-forging Hydraulic Press

Kong Xiangdong, Luo Hongliang, Quan Lingxiao, Lu Jianghui, Zhang Qiwei

2015, 26(22):  3087-3096. 

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In order to improve forgings performance and material utilization, a new kind of force closed-loop forging method was put forward. And its mathematical model was established, using the frequency domain analysis method, the influences of load stiffness on force control system features  were  studied.The dynamic performance was analyzed with AMESim and MATLAB/Simulink system. The effects of the PID controller, the integral separation controller and the fuzzy PID controller on the force closed-loop control performance of forging hydraulic press were  studied,and the simulation results were verified through the experiments.

Research on Several  Key Problems of Microflow  Extrusion  Forming  of  Ceramic  Slurry 

Zhou Jing, Duan Guolin, Lu Lin, Zhu Dongbin

2015, 26(22):  3097-3102. 

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According to the  theory of fluid mechanics,the flow shape of extrusion cavity die  was designed,which  was key part  of ceramic slurry microflow extrusion forming process.Using   ANSYS  software,the flow velocity of extrusion cavity die export cross section and the distribution of pressure within the flow field  were  simulated.The internal pressure field and outlet flow velocity distribution of four different flow shape extrusion cavity dies were  analyzed.The research  provides  the theoretical basis to solve the difficult problem of ceramic paste extrusion forming process and has a important reference value.

Research  on High Cycle Fatigue Properties for Welding Joints of   Simulating  Product of  Nuclear Power  Low  Pressure  Turbine  Rotors

Sun Lin'gen, Cai Zhipeng, Pan Jiluan, Liu Xia, Ding Yuming, Xu Xiaojin

2015, 26(22):  3102-3107. 

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The high cycle fatigue properties for submerged arc welding(SAW)  joints and tungsten inert gas(TIG) welding  joints of 25Cr2Ni2MoV simulating product of nuclear power low pressure turbine rotors were researched and compared.and the TIG welding joints were  found to be better.The interior crack origins of SAW were porosities and inclusions, while these of TIG were porosities. For the conditions of porosities,an approach to evaluate the high cycle fatigue properties was established with the measurement and calculation of characteristic size of crack initiation zones (without crack origins) and crack initiation rate. For the researched welding joints, white-light interfering profilometer was used to measure the characteristic size,and the crack initiation rate of TIG joint is lower, which is in agreement with the experiments.

Research Status and Analyses on  Accuracy  Retentivity  of  Domestic  CNC Machine Tools

Ma Junxu, Zhao Wanhua, Zhang Genbao

2015, 26(22):  3108-3115. 

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With a large number of  accuracy  survey on domestic CNC machine tools,it was  found that the number of accuracy recession caused by abnormal wear  gave a  bigger  proportion.In order to find the reasons of accuracy descends more clearly,the reasons that led  to the poor accuracy retentivity in the stage of design, manufacture and  applications were analyzed from three aspects of spindle accuracy, geometric accuracy and dynamic accuracy. Finally, aiming at the different types of CNC machine tools, the methods to  improve accuracy retentivity  were proposed.

Research Progresses on  Abrasive Fluid Jet Polishing Technology

Chen Fengjun, Miao Xiangliang, Tang Yu, Yin Shaohui

2015, 26(22):  3116-3123. 

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The mechanism of material removal in the process of polishing was discussed.The research results about jet machining system and platform were introduced.The development of mathematical model  of abrasive fluid jet were described,including speed change model,material removal model,surface evolution model,surface roughness model,numerical simulation model.The effect laws  of some major process parameters such as particle energy,jet pressure,abrasive,jet angle,stand-off  distance,additive on machining results were analyzed,and the research progresses  of  abrasive jet polishing technology were summarized,and the probable further  research  was  forecasted.